Influence of infill-wall modeling in the behavior of reinforced concrete frames
Alessandro Onofre Rigão1; Carlos Eduardo de Souza1; João Kaminski Junior1
1 Universidade Federal de Santa Maria
doi:10.20906/CPS/CILAMCE2017-0050
Resumo
The influence of the infill-wall on the lateral stiffness of buildings has been the subject of studies since the 1950s. One of the most accepted methods in the academic environment, easy to implement computationally, to simulate the contribution of the panels is the substitution by an equivalent diagonal modeled as a jointed bar. Many references in the literature make use of this concept, presenting different equations to represent the equivalent diagonal width. However this method is not able to represent adequately the change in straining in the boundary elements caused by the infill panels. Besides that, in some cases there is a dispersion of results when compared with more realistic methods. The use of structural model with more than one equivalent diagonal has shown more converging data for displacements and these are able to indicate better the stress-change in the frame boundary elements. The proposal of this work is to verify, through numerical simulation using a beam finite element, the change of the displacements and stresses in a reinforced concrete frame. Two models of equivalent diagonal are employed, namely Model A and Model B, but with use of two and three bars, adapted from literature proposals. These data are compared with simulation figures performed with micro-modeling using plane-stress finite elements. The displacements at the top of the frames in Model B are close to the reference plane model, in contrast with more significant differences from the order of 30% for Model A. Stress analysis are performed on two nodes of the frames, presenting more adequate values for Model B. As a conclusion, it is suggested to change the geometric parameters of the models and to compare them with other researchers' frames, aiming for greater reliability.
Palavras-chave: infill-wall; equivalent diagonal; masonry; finite element